1:7 or 1:9?
- Thread starter blackops
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Chris, I'm not into competition and I don't get paid to shoot anything period. This will just be my first AR and I want to be sure of what I'm getting into before I fork out 1500 for it. I got the Spikes 1:7. I'll plink with 55's and reload 75's if I plan a hunting trip.
If you do not have an opinion on the topic at hand please do not post trivial things just to up your post count.
I have a 1:7 barrel on my AR and it seems, so far, to run very well. I have used 62gn hand loads in it and had excellent results. I am looking at 69gr match bullets for my competition use. A bit of over kill for what I do but compared to loading 308, 223 is cheap.
I have not tried 55gr or lighter in it yet, but from everything I can gather it should shoot just fine. If I can get out to the range I will let you know. But my vote is for 1:7 too.
Are there any tactical rifle matches in your area? They are great fun and a great way to learn how to run your rifle. And did I mention they are more for than should be legally possible?
Some generalizations:
1. If you intend to shoot mostly 55-gr to 62-gr bullets (which are generally the most common and least expensive commercial ammo), then I suggest a 1:9 barrel. Accuracy will be no different, but the 1:9 barrel is most often cheaper.
The 1:7 barrels are generally more expensive, and will not add any accuracy until you get to heavier bullets (70-gr+).
2. If the 1:7 is the same price, and you do not intend to shoot bullets under 55-gr, then by all means, get the 1:7.
Do not think it is a magic potion for accuracy. More HP shooters prefer a 1:8 twist (usually 69-gr to 79-gr bullets), and folks that go longer like a 1:6.5 twist (and 90-gr+ bullets).
3. If you plan to regularly shoot bullets 70-gr and over, get the 1:7 (or a 1:8).
4. If you plan to regularly shoot under 55-gr bullets, get the 1:9 (or a 1:10 or 1:12).
1. If you intend to shoot mostly 55-gr to 62-gr bullets (which are generally the most common and least expensive commercial ammo), then I suggest a 1:9 barrel. Accuracy will be no different, but the 1:9 barrel is most often cheaper.
The 1:7 barrels are generally more expensive, and will not add any accuracy until you get to heavier bullets (70-gr+).
2. If the 1:7 is the same price, and you do not intend to shoot bullets under 55-gr, then by all means, get the 1:7.
Do not think it is a magic potion for accuracy. More HP shooters prefer a 1:8 twist (usually 69-gr to 79-gr bullets), and folks that go longer like a 1:6.5 twist (and 90-gr+ bullets).
3. If you plan to regularly shoot bullets 70-gr and over, get the 1:7 (or a 1:8).
4. If you plan to regularly shoot under 55-gr bullets, get the 1:9 (or a 1:10 or 1:12).
I believe that by limiting yourself to 1:9 twist, you will be excluding some fine rifles as options. ALL of the better rifles, BCM, Noveske, Spike's, Larue, etc. come with 1:7 twists and are not available (as far as I know) in a 1:9. 1:7 shoots 55gr projectiles just fine.
My Colt 20" HBAR came with 1:9, so I've had the chance to actually experiment a little, with both commercial loads, surplus, and handloads to see what it likes best. The surplus SS109 62gr loads are kind of the baseline, they shoot little groups at 100 yards consistently. The 55gr. surplus FMJ are almost, but not quite, as small. Handloaded 55gr Hornady flat-base hollowpoints group as well, or better, but the 55gr boattail bullets are not quite as accurate. I got some 63gr Sierra PSPs, and they shot acceptably for me, pretty close to the SS109s, but the 69gr Sierra Match Kings don't seem to like my rifle, for some reason, and I haven't been able to find a load with them that matches the plain NATO surplus stuff. Your mileage may vary.
christcorp
Member
Blackops; I understand what you're saying. And while I personally would never pay $1500 for an AR, you have to decide the purpose of buying the gun. If you plan on mainly punching paper at 100-200 yards and using it for defensive purposes, then it will never matter at all if it's a 1:7 or 1:9 twist. Any bullet from the 55g to 75g will do exactly what you want it to. If you plan on shooting varmints, prairie dogs, coyote, targets, etc... at 300 yards, then your accuracy probably needs to be much better. Therefor, a 1:7 would be a better choice if using the heavier bullets. I shoot prairie dogs a lot. Small little critters. But I usually use 55 or 62 grain bullets to do that. At normal paper punching distances; and home defense; I don't care if the bullet is 55g or 80g, it will still hit your target at those distances.
But you already bought your AR, and it has a 1:7 twist barrel. So it doesn't really matter what is said here. You have what you have. My comment is more intended for the individual who hasn't bought their rifle yet, but are looking. Those of you in this situation, DO NOT WORRY about any of this barrel twist stuff, unless you plan on shooting competition, marksmanship, etc... or you plan on hunting with the 75-80 grain bullets at the 300+ yard mark. That's the only time when the barrel twist mast become significant. For the <300 yard shots; shooting targets; and defensive purposes, the barrel twist doesn't matter. The heavier bullets will work just fine in any of them. So; if you happen to find the rifle you like, but it has a 1:9 barrel; don't discard that rifle as an option and automatically spend hundreds of dollars more on a rifle that has a 1:7 twist. It's not that important.
Bartholomew Roberts
Member
christcorp said:
Actually, when I tested this many years ago out of my Bushmaster 1:9 16" HBAR, I didn't have that experience. I got about 4-5" at 100yds with Black Hills 75gr Match ammo. At 200yds the groups were around 20" and we ran out of ammo before we could push it to 300yds and test that out.
That is going from memory of course; but the original post of those results is in the archives here somewhere. However, I'd hesitate to say that any 1:9 will shoot 75gr just fine out to 300yds in every instance, though I don't doubt there are 1:9 barrels that are quite capable of it.
christcorp
Member
A lot depends on the ammo; but also sights. If you're trying to hit >100 yards with open iron sights or 1x Red-Dots, then you'll be lucky to hit anywhere near the target. (Not saying that you are). But when I've sighted numerous rifles in at 200 yards, I've been able to hit the target at 300 yards with 70+ grain bullets. Am I going to get those 1-2 MOA that some people want? Nope; not going to happen.
But i have to keep emphasizing what the gun will be used for; and whether or not you want to spend the extra strictly for the 1:7 twist barrel instead of a 1:9. Where I live, big game hunting: Antelope, Deer, Elk, Moose, Sheep, etc... is NOT ALLOWED to be shot with anything smaller than a .243. So, I'm not going to use an AR for hunting large animals. So, what other reason would I NEED a 75 grain bullet? Honestly; I can't think of one possible reason that I would need a 70-80 grain bullet.
1. Self Defense? No. Self defense isn't done at 100+ yards. Jury probably wouldn't even buy the self defense argument at 50 yards. So assuming you did use the 1:9 barrel for Self Defense, it wouldn't matter what size bullet was it it. It would hit your target.
2. Target Practice? No. If I'm going to shoot paper, I'm going to shoot the cheaper 55 or 62 grain. Matter of fact; I usually shoot steel case russian ammo at <$5 a box.
3. Varmint, Rabbit, Prairie Dog, Coyote, etc...? No. No matter what twist barrel I had, I'd want to use the lighter 55-62 grain bullet anyway.
The only reason I can even imagine using 70-80 grain .223 bullets is either: Large game hunting; which I'm not ALLOWED to do, or competition shooting which requires highly accurate match type ammo; which I'm not into.
So my original advice still stands for the majority of potential AR owners. Don't spend the extra for the 1:7 barrel if it will cost you more if you're not into competition shooting, or plan on shooting past 300 yards and in both cases you feel you NEED the larger bullet for match or hunting. Each person has to answer this question for themselves. "What Would I Use a 75 grain Bullet For"????? If you feel you would need to use a 75 grain bullet, the next question has to be: "Will I be shooting at 300 yards and need the type of accuracy I get at 100 yards"? If the answer is yes, then get the 1:7 barrel. if the answer is no, and you can get the same quality of barrel for a significant savings if it's in the 1:9 barrel; then think hard about it. I got my M&P15 on sale last month. Retail was $1069, but final price after sales and rebates was $649. At that savings, I didn't care if it was 1:7 or 1:9 Hell, I can buy a complete new upper and still be at less than the original price of the M&P. So again; decide what you're going to use the rifle and possibly a 70-80 grain bullet for, and at what distance, and you'll know what and how much to spend on a barrel.
Bartholomew Roberts
Member
I've shot out to 600yds with this particular 16" 1:9 HBAR, so I feel comfortable with the platform and its ability to perform with lighter loads. At the time I did this test, a typical 5rd group of Santa Barbara SS109 from the bench would be under 2".
However, I do not consider 4-5" with match ammo at 100yds or 20" at 200yds to be acceptable performance - and the 200yd performance is pretty much unacceptable for any use. So I am taking issue with your statement that heavier bullets are just fine under 300yds in all 1:9 barrels. They aren't fine in every single 1:9 barrel, though some 1:9 barrels do perform well with them.
As a result, I think your premise regarding "Will I be shooting at 300 yards and need the type of accuracy I get at 100 yards"? " is fundamentally flawed since I think there are 1:9 barrels out there that won't deliver that kind of accuracy with heavy bullets at 200yds, let alone 300yds. Otherwise, I think you have a good, practical analysis going.
However, I do not consider 4-5" with match ammo at 100yds or 20" at 200yds to be acceptable performance - and the 200yd performance is pretty much unacceptable for any use. So I am taking issue with your statement that heavier bullets are just fine under 300yds in all 1:9 barrels. They aren't fine in every single 1:9 barrel, though some 1:9 barrels do perform well with them.
As a result, I think your premise regarding "Will I be shooting at 300 yards and need the type of accuracy I get at 100 yards"? " is fundamentally flawed since I think there are 1:9 barrels out there that won't deliver that kind of accuracy with heavy bullets at 200yds, let alone 300yds. Otherwise, I think you have a good, practical analysis going.
How about this for a monkey wrench in all of the theories. I had a White Oak barrel with a 1:7 twist that shot its best groups with 52gr HPs. You just never can tell, really. I know of at least two ARs with 1:9 twist barrels that will hold right at MOA with 77gr SMK handloads. There will always be exceptions to the rule, I suppose.
HorseSoldier
Member
Mk 262 seventy-seven grain ammo is very lovely stuff for a fighting rifle, but I agree with the above point entirely -- civilian self defense shootings occur at a range where none of the performance it yields will matter. Honestly, at self-defense ranges you could shoot 62+ grain ammo through a 1-12 twist barrel and would tend to get acceptable results (i.e. hits on a bad guy or bad guy sized target) even if the group sizes would look embarrassing on the flat range.
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